Indoor cycling burns roughly 210 to 441 calories in 30 minutes, depending on your body weight and how hard you push. A 155-pound person pedaling at a moderate pace burns about 252 calories in half an hour, while ramping up to vigorous effort pushes that closer to 378. Those numbers scale up or down with your weight, your resistance settings, and how long you ride.
Calorie Burn by Weight and Intensity
Harvard Health Publishing provides some of the most widely cited estimates for stationary cycling. These are for 30 minutes of continuous riding:
- 125-pound person: 210 calories at moderate intensity, 315 at vigorous intensity
- 155-pound person: 252 calories at moderate intensity, 378 at vigorous intensity
- 185-pound person: 294 calories at moderate intensity, 441 at vigorous intensity
To estimate a full 45- or 60-minute session, you can scale these numbers proportionally. A 155-pound rider working at moderate effort for 45 minutes would burn roughly 378 calories. A full hour at vigorous effort for a 185-pound rider lands in the neighborhood of 880 calories. These are estimates, not exact figures, but they give you a reliable ballpark.
What Counts as Moderate vs. Vigorous
The difference between moderate and vigorous cycling isn’t just about how hard it feels. Exercise scientists assign each intensity level a MET value, which represents how many times more energy you burn compared to sitting still. Sitting on the couch is 1 MET. The Compendium of Physical Activities breaks stationary cycling into several tiers:
- Light effort (30-50 watts): 3.5 METs
- Light to moderate (51-89 watts): 4.8 METs
- Moderate to vigorous (90-100 watts): 6.8 METs
- Vigorous (101-160 watts): 8.8 METs
- Very vigorous (201-270 watts): 14.0 METs
A typical spin bike class is rated at 8.5 METs, which places it solidly in vigorous territory. If your bike displays wattage, that number is the single best predictor of how many calories you’re actually burning. A rider producing 150 watts is doing meaningfully more work than one producing 90 watts, regardless of how sweaty either person feels.
What a Spin Class Actually Burns
A 45-minute group cycling class typically burns between 400 and 600 calories. That wide range reflects real differences between riders. A lighter person pedaling at the suggested resistance will land near the lower end, while a heavier person pushing hard through every interval will approach the upper end.
Class format matters too. A ride built around repeated high-intensity intervals will burn more per minute than a steady-state endurance ride at the same duration. The intervals force your body to work harder during recovery segments, keeping your overall energy output elevated even when cadence drops.
Resistance, Cadence, and Power Output
One common question is whether it’s better to crank up the resistance or spin your legs faster. The answer is that neither matters independently. What drives calorie burn is power output, measured in watts. You can hit 150 watts by grinding a heavy gear slowly or by spinning a lighter gear quickly. As long as the wattage is the same, the calorie cost is essentially the same.
That said, the two approaches train your body differently. Higher cadence at lower resistance builds cardiovascular and aerobic fitness. Lower cadence at higher resistance challenges your muscles more. If your goal is purely calorie burn, hit whatever combination of resistance and cadence lets you sustain the highest average wattage for the full ride. If your bike doesn’t display watts, perceived effort and heart rate are your next best guides.
How Accurate Is Your Bike’s Calorie Counter
Most stationary bikes and fitness trackers overestimate calorie burn, sometimes significantly. Research from Harvard’s School of Engineering found that wearable devices can have error rates between 30 and 80 percent for calorie estimates. The calorie number on your bike’s screen is better thought of as a relative benchmark. If last week’s ride said 400 calories and this week’s says 450 at the same duration, you probably did work harder. But the absolute number is likely inflated.
Bikes that measure actual power output in watts tend to be more accurate than those relying only on heart rate or generic algorithms. If you want a closer estimate, you can calculate it yourself: multiply your weight in kilograms by the MET value for your intensity level, then multiply by the duration in hours. For a 70 kg (155-pound) person riding at 8.5 METs for 45 minutes, that works out to roughly 70 × 8.5 × 0.75 = 446 calories. It’s still an estimate, but a more grounded one than most screen readouts.
The Afterburn Effect
Your body continues burning extra calories after you stop pedaling, a phenomenon called excess post-exercise oxygen consumption. The size of this afterburn depends heavily on how hard you worked. Studies on cycling show the range is modest for moderate efforts: about 15 to 35 extra calories after a 30-minute session at moderate intensity. Longer, harder rides produce more. Eighty minutes of cycling at 70% of maximum effort led to roughly 130 extra calories burned afterward in one study.
Interval training amplifies the effect. Research comparing 30 minutes of steady cycling to 20 one-minute intervals at maximum effort found the interval group burned about 75 extra calories afterward, compared to roughly 35 for the steady-state group. That’s a meaningful difference, but it’s worth keeping in perspective. The afterburn from a typical indoor cycling session adds somewhere between 15 and 75 calories on top of what you burned during the ride. It’s a nice bonus, not a game-changer.
How Indoor Cycling Compares to Outdoor Riding
Indoor and outdoor cycling burn calories at similar rates when the effort level is matched. The key difference is consistency. On a stationary bike, you never coast downhill, stop at traffic lights, or benefit from a tailwind. Every second of a 30-minute indoor ride involves active pedaling. Outdoor rides, by contrast, include stretches where momentum carries you forward with minimal effort. For a given block of time, indoor cycling often delivers more total work simply because there’s no coasting.
Outdoor riding does add small energy costs that don’t exist indoors, like balancing the bike and dealing with wind resistance. But these factors are minor compared to the advantage of uninterrupted pedaling on a stationary bike. If you’re choosing between the two purely for calorie efficiency per minute of available time, indoor cycling has a slight edge.